What happened was that a rumor began to spread that the name of the killer was Ryan. I don't know the source of the rumor but I'm almost certain that the name didn't come from an official police source. This is when the madness begun, when people confused this rumor with a fact. Large media companies, such as CNN and Fox News, did also confuse this rumor with a fact, and began spreading the picture and name of the unjustly accused Ryan. The hunt continued when people began accusing Twitter-accounts with names that resembled the name of the innocent Ryan. You could hear that these innocent randomly accused persons should "burn in hell," and they had to defend themselves against these faulty accusations:
"haha i didnt kill anyone, stop spamming my twitter please. and all my other tweets were just jokes because i only had around 20 followers"The only fact we knew was that the real killer had died at the crime scene, but what would have happened if he hadn't died? What would have happened if he head escaped from the scene? Would people began searching for these faulty accused Ryan's? According to Ryan's Facebook page, he took the bus home from his job and was unaware that his picture was all over the world. What if someone had recognized him on the bus and decided to the take law in his own hands? Luckily no-one was physically damaged from these faulty accusations.
One other thing I noticed was that people didn't believe that Ryan was innocent when people on Twitter told them that he was alive and couldn't have been the killer. The reason to why they didn't believe them was that they had seen his picture in the large media sites like CNN, and said that media were never wrong. But media were wrong since they had also confused the rumor with fact.
Later, things went totally out of control on both Twitter and Facebook. People began creating fake Facebook accounts and pretended to be the killer (media had now learned their lesson and were not fooled by the trick), people accused both the innocent Ryan, as well as his brother Adam and said that they had worked together, and more innocent Twitter accounts were accused, including Adam_LZ who's name was almost like the name of the real killer, but the real meaning of LZ was far from the surname of the real killer.
Some videos on the behavior of crowdsA comic book fair in Japan (The dark picture will disappear at around 1:30):
A Victoria's Secret store during the Black Friday sale in the US:
A traffic intersection in India:
The Sasquatch music festival:
If you would like to learn more, you should listen to this excellent podcast by the BBC: Crowd Psychology